Method of soil stabilization and leakage prevention

ABSTRACT

The present invention relates to the method of soil stabilization and leakage prevention by means of a so-called &#39;&#39;&#39;&#39;chemical grout&#39;&#39;&#39;&#39; using synthetic resin compositions which comprise a strong alkaline phenol formaldehyde resin liquid and a required hardening agent and/or a suitable gelation inhibitor, for example, by filling the said resin composition into the crevices and cracks of the rock bed, construction joints of concrete dam, voids of gravel, etc., for the prevention of leakage, and by grouting the said resin composition into soft ground for solidification, or by grouting into the wall of petroleum well for the prevention of crumbling and other applications for the prevention of seepage of spring water which occurs frequently in the various civil engineering works.

United States Patent [72] Inventors Takao Murata Yaizu; Atsushi Kudo,Fujieda, both of, Japan [21] Appl. No. 746,530 [22] Filed July 22, 1968[45] Patented Aug. 17, 1971 [73] Assignee Sumitomo Durez Company, Ltd.Tokyo, Japan [32] Priority July 24, 1967 [33] Japan [31] 42/47187 [54]METHOD OF SOIL STABILIZATION AND LEAKAGE PREVENTION 5 Claims, 1 DrawingFig.

[52] 11.8. C1 61/36, 166/295, 260/17.5, 260/29.3, 260/51.5, 260/59 [51]Int. Cl E02d 3/12, E2 I b 33/13 [50] Field of Search 260/1 7.5, 29.3,29.4, 78.3; 166/295; 252/85; 61/36 R [56] References Cited UNITED STATESPATENTS Re 23,393 7/1951 Kurtz et al. 166/22 Primary Examiner-Harold D.Anderson Assistant Examiner-E. Nielsen AttorneysPeter F. Casella andJames F. Mudd ABSTRACT: The present invention relates to the method ofsoil stabilization and leakage prevention by means of a socalledchemical grout using synthetic resin compositions which comprise astrong alkaline phenol formaldehyde resin liquid and a requiredhardening agent and/or a suitable gelation inhibitor, for example, byfilling the said resin composition into the crevices and cracks of therock bed, construction joints of concrete dam, voids of gravel, etc.,for the prevention of leakage, and by grouting the said resincomposition into soft ground for solidification, or by grouting into thewall of petroleum well for the prevention of crumbling and otherapplications for the prevention of seepage of spring water which occursfrequently in the various civil engineering works.

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-24 nummumazou V mmnmmuma METHOD OF SOllL STABILIZATION AND LEAKAGEPREVENTION More particularly, the present invention relates to a methodof soil stabilization and leakage prevention whereby a resin compositioncomprising a water soluble strong alkaline liquid phenol formaldehyderesin with a pH of 9.5 or more and having a molar ratio of phenol toformaldehyde between 1:15 and 1:3.0, and a lactone which amounts to l to30 percent by weight of the liquid resin and which acts as a hardeningagent, and sometimes an adequate amount of alcohol added as a gelationinhibitor to the said mixture, is grouted into rock bed, concrete damwork joints, a gravel layer, weak ground or an oil well, etc., and thenhardens at normal temperature within the required time not only in thevoids of the soil or sand grains but also in the presence of water oroil.

Usually, for such kind of soil stabilization and leakage prevention, anaqueous cement suspension, water glass (sodium silicate), an aqueousemulsion of bituminous material, chrome-lignin or acrylamide, etc. areused. An aqueous cemerit suspension can be handled and grouted verysimply and performance is excellent for the' leakage prevention for hardground having a wide opening such as a crack in rock bed or for thereinforcement of bearing power of ground foundation; however, when itcomes to an opening narrower than 0.1 millimeter, it is difficult togrout the crack. Also this usual method is unfit for use in thoseinstances where it is needed to harden the grouted liquid rapidly, forit usually takes several hours for hardening.

Water glass is applied either as a single liquid or as a mixture of twoliquids. It is comparatively easy to adjust its hardening time bychanging the hardening agent. It is characterized by imparting higherstrength to the ground foundation after hardening of the grouted liquid.It is generally used in cases for need of rapid curability and highstrength. But since its viscosity as grouting liquid is highercomparatively in the range of 40 to 60 centipoises, it is difficult togrout a narrower opening.

Chrome-lignin is prepared as a grouting liquid by using pulp wasteliquor with bichromates as its main raw materials; during the earlyperiod following its preparation, it has good pr..- colating propertiesfor fine openings similar to acrylamide described below. But there are afew faults. One needs to raise gradually the viscosity of the preparedliquid. Scores of minutes and/or several hours are needed to finish thehardening process, and even then the ground foundation has relativel yweak strength after curing, and so forth.

Acrylamide is being used most widely at present as a chemical groutliquid agent. lts hardening takes place almost instantaneously after adefinite time following preparation of the liquid and its viscosityprior to the start of hardening is 1.2 centipoise which is approximatelythe same as that of water, so it has a characteristic of being able topercolate into minute cracks, but it has a disadvantage of being moreexpensive.

There are some method of use inventions already patented which claim theuse of liquid phenol formaldehyde resin as a chemical grouting agent.For example, in US. Pat. No. 2,485,527 a phenol-formaldehyde resinliquid is prepared from reacting alkaline phenol and formalin and thenneutralizing after washing with water, followed by partial reaction withresorcinol. For actual application of the said reaction product, it ishardened by use of an aqueous sodium hydroxide solution. Thedisadvantage of this resin lies in its need of a large amount ofexpensive resorcinol, so it is considered that feasibility of practicaluse of this resin in the field of the civil-engineering works isunlikely for some time to come. Accordingly, although it is worthconsidering means of adjustment of the cost by decreasing the amount ofresorcinol in this case, this will lead to a longer time required forhardening and difficulty in hardening when it is in presence with oiland/or salts. Moreover, it has a disadvantage of being temperaturesensitive which causes much delay in hardening at temperatures from 5 toC., and so forth.

The present invention is a method of soil stabilization and leakageprevention characterized in that a strong alkaline liquid phenolformaldehyde resin overcomes those defects described hereinbefore and iscomparatively low priced, which is blended with lactones and then themixture is easily grouted into the required soil and readily hardenstherein.

The inventors have found the usefulness of a water soluble stronglyalkaline liquid phenol formaldehyde resin having a molar ratio of phenolto formaldehyde between 121.5 and 1:3.0 with a pH of 9.5 or more whichrapidly cures in soil when admixed with lactones even in the presence oflarge amounts of water, so that prevention of leakage is secured by itsability to fill crevices or cracks of rock bed, or construction jointsof a concrete dam, voids of gravel (layer), and other emergencyapplications for leak prevention of spring water which occur frequentlyduring various civil-engineering works. Moreover, easy permeation ofsoft ground by the resin adds reinforcement to it or prevents collapseof the wall of a petroleum well.

However, in case of a molar ratio of phenol to formaldehyde less than1:1.5, insufficient gelation or only a slight increase in viscositywithout gelation occurs to the liquid phenol formaldehyde resincomposition herein in admixture with lactones, regardless of the pH ofthe liquid resin. And in case of a molar ratio of phenol to formaldehydemore than 1:1.5 and with a pH of 9.5 and/or less, gelation does not takeplace until addition of lactones surpasses more than 30 percent of theresin. Should gelation be required in such a case, increasing thetemperature is necessary for the addition of large amounts of lactones.

In realizing the present invention, in order to make a strong alkalineliquid phenol formaldehyde resin, more than 9.5 in pH value, it ispreferable to use caustic soda, but caustic potash, calcium hydroxide orbarium hydroxide, etc. also may be used, and in these cases they showsubstantially the same effect as caustic soda.

And by replacing a part of phenol of the composition of the strongalkaline liquid phenol formaldehyde resin described herein, withcresols, resorcinol, urea, melamine or lignin, and so on, substantiallythe same effect can be obtained.

in the present invention, it is most preferable to use [3- propiolactoneas a hardening agent and also there are other lactones which can berecommended, such as B-butyrolactone, y-butyrolactone, caprolactone,valerolactone, etc. Mixtures of lactones can also be used. Each oneshows a remarkable effect as hardening agent, that is, they increase therate of polymerization of the phenol-formaldehyde resin. Alsoeffectiveness of soil stabilization and leakage prevention appears to beunexpectedly superior to use of either the lactone alone or the phenolformaldehyde alone, or to what would be expected from using the twoadditively. The required quantity of these lactones to be added to thestrong alkaline liquid phenol-formaldehyde resin, is between l and 30percent by weight of the resin and most preferably in the range of 4 to15 percent. If the added amount is less than 1 percent, gelation doesnot take place at all or too slowly at room temperature. Moreover, whenthere is a large amount of water in the grouting liquid, it is preferredto increase the quantity of lactone added, but the exact amount shouldbe also regulated in accordance with difference in composition of thestrongly alkaline liquid phenolformaldehyde resin. Although sufficientgelation occurs when addition of lactones to the liquidphenol-formaldehyde resin exceeds 30 percent, and therefore does notcontradict in any way the objects for practical use of the presentinvention, it has a disadvantage of requiring more care in handling andmoreover leads to a substantial rise in cost as a grouting liquid.

Moreover, the inventors have found that methanol, ethanol, butanol,propanol, ethylene glycol, glycerine or other polyhydric alcohols areeffective as gelation inhibitors.

To sum up the excellent characteristics of the method of soilstabilization and leakage prevention according to the present invention,they are as follows:

1. It hardens within an optional required time even in coexistence withwater, oil, inorganic salts, or sulfides, etc.,

ssfts e tsfp tm ib itxi soilbefore grouting respectively in anyproportion, and imparts strong bonding strength to rock beds or soilsand grains.

'2. The grouting liquid retains its low viscosity until start of itshardening (or gelation), so it percolates into very small openings. Andalso it hardens under lower temperature, somewhere below C.

. lt hardens even in acidic or alkaline soil, and the resulting soilstrength after hardening of the liquid resin increases to about kg./cm.

4. Hardening proceeds rapidly from a state of low viscosity to a gelledform similar to an addition polymeric resin. Moreover, the resultinghardened substance retains its hydrophilic property.

5. The process of grouting is simple and does not require any specialmachine or equipment.

The following examples are presented in order to define the inventionmore fully without any intention of being limited thereby. All parts andpercentages described therein are by weight unless specified otherwise.

EXAMPLE 1 Phenol (1,000 parts), 1,700 parts of formalin (37 percentformaldehyde), and 300 parts of aqueous sodium hydroxide solution (30percent caustic soda) were charged into a reaction vessel and reacted 30to 40 minutes at 98 to 100 C. The end point of the reaction of thisphenol-formaldehyde resin liquid was decided by its viscosity at 25 C.The properties of the resulting resin liquid was usually as follows:

Appearance brown liquid Specific Gravity (at 25 C.) 1.190

Viscosity (at 25 C.) 1--3 poises Gelation Time (at 130 C.) -25 minutes-Solid Content 48-50% pH 10-1 I Water Tolerance more than 20 times 'wiltataag ingtargasioaaitazis a dae'a to this strong alkaline liquidphenol-formaldehyde resin, it gelled rapidly at room temperature.

A grouting liquid for soil stabilization was made according fi t sf w erm??? The liquid resin 100 parts Water 200 parts fi-Propiolactone 8parts integrating iiquaraamarta herein had a very '13.. viscosispecimen,the resin composition is transferred from 1 to 2 by.

compressed air supplied by 4, under fixed pressure adjusted withpressure gauge 6, and is thus percolated into the soil 5 which is tampedpreviously to a condition having a known Coefficient of permeability of3.6 8xl0' cm./sec.

Pressure of grouting 1 kgJm'it.

The resulting coefficient of permeability of the test specimen after 3hours from the grouting was 8. 1 7X10 cm./sec.

Furthermore compressive strengths by an uniaxial test after 3 hours and24 hours standings, respectively, from the grouting on the same testspecimen were as follows:

The results described above, clearly indicate that the resin compositionis well sufficient and effective for soil stabilization and leakageprevention.

EXAMPLE 2 Phenol (800 parts), 200 parts of urea, 1,700 parts of formalin-(37 percent aqueous formaldehyde solution) and 30 percent aqueouscaustic soda solution were charged into a reaction vessel, and reacted30 to 40 minutes at 98 to 100 C. The end point of the reaction wasdecided by. viscosity of this reacted phenol-formaldehyde resin liquidat 25 C. The properties of the resulting resin liquid were as follows:

Appearance brown liquid Specific Gravity (at 25 C.) 1.190

Viscosity (at 25 C.) l 3 poises Gelation Time (at C.) z 20 30 minutesSolid Content 4850% Water Tolerance more than 20 times When 4 to 10percent of B-butyrolactone was added to the liquid phenol-formaldehyderesin obtained hereby, it gelled rapidly at room temperature. Therefore,the resulting resin can be used as a soil stabilizing agent just likethe phenol-formaldehyde resin liquid as described in example 1.

What we claim is:

l. The method of soil stabilization and leakage prevention comprisingintroducing into the formation to' be treated a composition comprising awater soluble strongly alkaline liquid phenol-formaldehyde resin havinga pH of at least 9.5 and having a molar ratio of phenol to formaldehydebetween 1:1.5 and 1:30, and a lactone which is employed in a proportionof l to 30 percent of the liquid resin.

2. The method of claim 1 wherein an alcohol is employed in I saidcomposition as a gelation inhibitor.

3. The method of claim 1 wherein a part of the phenol in thephenol-formaldehyde resin is replaced by a compound selected from thegroup consisting of melamine, urea, lignin, cresols and resorcinol.

4. The method of claim 1 wherein the lactone is betabutyrolactone.

5. The method of claim 1 wherein the lactone is betapropiolactone.

F050 UNITED STATES PATENT OFFICE CETIFIQATE @F mREcTm Patent No. 3, 599,33 Dated August 7, 197? Inven Takao Murata and Atsushi Kudo It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

On the front page, after "ABSTRACT" read --A methed of soiistabiiization and Eeakage prevention characterized by using a resincompoaiti on which compfises a water soiubie strongiy alkaiine iiquidphenoi formaiciehycie resin with a pH of 9,5 or more and having a molarratio of phenoi to formaidehyde between i :1 .5 and 1 :3.0 and a iactonewhich is added in a proportion cf i to 30 percent of the liquid resinaAn a'icohoi may be adc'ied as a eEat-IQn inhiizvi tor, if required.

Column 3 line 63, For 3. 68 x 10 read 3.68 x 10 Column Hne 2, for "8.17x 10 read 8.17 x 10 igned and sealed 'thi s 25th day of A il 1972.

EDWARD MiPLbWCi-IER ,J? ROBERT GOTTSCHALK 1109? Commissionerof Pa tan ts

2. The method of claim 1 wherein an alcohol is employed in saidcomposition as a gelation inhibitor.
 3. The method of claim 1 wherein apart of the phenol in the phenol-formaldehyde resin is replaced by acompound selected from the group consisting of melamine, urea, lignin,cresols and resorcinol.
 4. The method of claim 1 wherein the lactone isbetabutyrolactone.
 5. The method of claim 1 wherein the lactone isbetapropiolactone.